The AC Engine Project - Brief walk through of what it is all about.
1. My 16/80 engine was extremely corroded and whilst I seriously contemplated having the water jacket replaced (an option that does seem to work) my engineering assessment suggested that I would still have a 70 plus year old block with all its frailties, and restrictions in regard to bottom end strength, oil sealing, let alone the front water entry also being corroded; This was an unacceptable compromise for a car worthy of much better.
2. Being aware that new blocks were available in the 80's, which Werner Oswald had made, unfortunately none were available so where was the tooling I could possibly borrow to have some castings from? After some investigations I determined they were in a garage in Germany, I also found that they either belonged to the Club being donated by Werner or were still the property of Werner, as an aside. In the process of contacting the owner of the garage I found that somebody had acquired the tooling just a few days before I had a reply to my letter which effectively stopped me form having the benefit of them.
3. In the meantime I decided that more parts were needed along with the block to enable a fully reconditioned engine, so not wishing to go it alone setting up a supply source for parts, I had discussions with a potential partner to share the project. I negotiated with AC Ltd for purchase of drawings & technical information then shared the information with the potential partner to find that we were not in full agreement in terms of re-engineering and investment so we agreed to go on our separate paths.
4. New blocks were still required (one for my racing special), I also believed that significant improvements were possible and sensible whilst still maintaining the respected Weller design; that if I invested in new tooling all these improvements could be incorporated which allowed significant strength improvements, facilitate the use of Crankshaft Dampers on pre war & post war engines, as well as many other improvements. As I had decided to have tooling made I also opted to have both PVT & post war designs made so all the improvements could be available to virtually all models of AC Weller engined cars!
5. In the Engineering evaluation it was apparent that the rotating parts needed to be improved which included large diameter main and big end journals, knowing that several replacement crankshafts had failed it was thought essential to have crankshaft & Connecting rods designed; I commissioned an experienced design engineer to this task.
6. Parallel to this I also decided that a design study was needed for the cylinder head, camshaft and valve system, so a design program was initiated which resulted in a completely new camshaft design together with higher ratio rocker system geometry valve specifications; and ultimately head porting shape and sizes. Part of this design process was to use better and more available components such as bearings, valves; springs etc, such that they could be sourced local to the owners and not have the problem of restricted availability and supply. I did not wish to stock everything myself and have the problem of high parts cost due to small batch production. A note: the valve system needed re-specifying to eliminate frailties of the AC Original design, particularly the springs.
7. A number if ingredients were needed to ensure the success of the project, time, funds, good skills and manufacturing sources, I was approaching retirement, decided I needed an active (and stressful!) hobby, that solved one element. Having trained in Engineering and spent all my working life in product based industries I felt able to find the specialist skills needed, that and given the belief that the investment costs could be covered over time I was prepared to invest. One other essential needed: the project must not be relied upon as a revenue stream, if it paid the investment back sometime that would be acceptable.
We are all aware that the skills base in the UK is diminishing, I do not believe this scale of project will be possible in the near future, the technical skills will only be embedded in large industry & the craft skills will be extinct, so small batch manufacture will be difficult; I fear this and just hope it will not be true.
8. The objective to produce the best Weller engine possible whilst ensuring it and the major parts were generally interchangeable with existing engines, also that gaining VSCC approval for the parts to be used in competition was very important. The cost of parts is also very important, which unfortunately is a function of quantities to be made, it must be understood that we are in a small batch production almost bespoke! However to be fair, some volume quality car manufacturers supply their comparable replacement parts at quite high cost?!
9. With the major components re-engineered I felt it essential to have some of the important accessories improved, particularly the oil pump, filtration and supply system; this meant a redesign of the sump to accommodate a larger oil pump (in production), spin on filter and the pressure relief valve (in the correct position after the filter). All this work is completed with parts on the shelf or nearly. The PVT water pump was a problem so that has been re-designed & appears to work well, better starter motors were thought essential using pre engaged high torque motors - now available.
10. After a frustratingly long delay I have now received the new design cylinder head casting in Aluminium which has the potential for improved porting and will fit Vintage, PVT & post war engines. This together with the new Camshaft and rocker design will with some confidence offer significant performance improvements whilst still conforming to the original design concept. I find we are now entering the "exciting period" of nearing a complete engine build which I hope will be done this year, this will incorporate all the above and along with better rocker shafts, flywheels, liners and pistons.A new head gasket is in progress which I hope will offer better sealing performance so there is still some work to do, not least a better Rocker/Camshaft cover to top it all off.
11. The next part of the program will be engine performance trials, development of the carburetion and ignition systems; these will require the support of experts in this field, but this can be done progressively, and by other users who require different results - whether it be general road performance, sprinting, track work or hill climbs.The Weller engine is well thought of by both AC Owners & Frazer Nash Owners, the overriding objective has developed to achieve at least as good performance as the BMW 328/Bristol engines and if this is attained perhaps the original AC ACE Owners will suddenly find respect from the Bristol engined car owners and match their competitive performance! - with a simpler (superior) engine.
All the information on the project is available on my web site ' www.ac-engine.com ' it will be updated periodically but attached are some pictures of the various parts which essentially can be fitted to existing engines with some restrictions, I am more than happy to discuss the project with interested people & have I hope given assistance to people already. I have invested a great deal of time & capital, it would be nice if this can be available to others, I will have my own engines assembled soon & fitted to my cars. I hope you find this project of interest.
Robin A Woolmer
AC Engine Project
1. My 16/80 engine was extremely corroded and whilst I seriously contemplated having the water jacket replaced (an option that does seem to work) my engineering assessment suggested that I would still have a 70 plus year old block with all its frailties, and restrictions in regard to bottom end strength, oil sealing, let alone the front water entry also being corroded; This was an unacceptable compromise for a car worthy of much better.
2. Being aware that new blocks were available in the 80's, which Werner Oswald had made, unfortunately none were available so where was the tooling I could possibly borrow to have some castings from? After some investigations I determined they were in a garage in Germany, I also found that they either belonged to the Club being donated by Werner or were still the property of Werner, as an aside. In the process of contacting the owner of the garage I found that somebody had acquired the tooling just a few days before I had a reply to my letter which effectively stopped me form having the benefit of them.
3. In the meantime I decided that more parts were needed along with the block to enable a fully reconditioned engine, so not wishing to go it alone setting up a supply source for parts, I had discussions with a potential partner to share the project. I negotiated with AC Ltd for purchase of drawings & technical information then shared the information with the potential partner to find that we were not in full agreement in terms of re-engineering and investment so we agreed to go on our separate paths.
4. New blocks were still required (one for my racing special), I also believed that significant improvements were possible and sensible whilst still maintaining the respected Weller design; that if I invested in new tooling all these improvements could be incorporated which allowed significant strength improvements, facilitate the use of Crankshaft Dampers on pre war & post war engines, as well as many other improvements. As I had decided to have tooling made I also opted to have both PVT & post war designs made so all the improvements could be available to virtually all models of AC Weller engined cars!
5. In the Engineering evaluation it was apparent that the rotating parts needed to be improved which included large diameter main and big end journals, knowing that several replacement crankshafts had failed it was thought essential to have crankshaft & Connecting rods designed; I commissioned an experienced design engineer to this task.
6. Parallel to this I also decided that a design study was needed for the cylinder head, camshaft and valve system, so a design program was initiated which resulted in a completely new camshaft design together with higher ratio rocker system geometry valve specifications; and ultimately head porting shape and sizes. Part of this design process was to use better and more available components such as bearings, valves; springs etc, such that they could be sourced local to the owners and not have the problem of restricted availability and supply. I did not wish to stock everything myself and have the problem of high parts cost due to small batch production. A note: the valve system needed re-specifying to eliminate frailties of the AC Original design, particularly the springs.
7. A number if ingredients were needed to ensure the success of the project, time, funds, good skills and manufacturing sources, I was approaching retirement, decided I needed an active (and stressful!) hobby, that solved one element. Having trained in Engineering and spent all my working life in product based industries I felt able to find the specialist skills needed, that and given the belief that the investment costs could be covered over time I was prepared to invest. One other essential needed: the project must not be relied upon as a revenue stream, if it paid the investment back sometime that would be acceptable.
We are all aware that the skills base in the UK is diminishing, I do not believe this scale of project will be possible in the near future, the technical skills will only be embedded in large industry & the craft skills will be extinct, so small batch manufacture will be difficult; I fear this and just hope it will not be true.
8. The objective to produce the best Weller engine possible whilst ensuring it and the major parts were generally interchangeable with existing engines, also that gaining VSCC approval for the parts to be used in competition was very important. The cost of parts is also very important, which unfortunately is a function of quantities to be made, it must be understood that we are in a small batch production almost bespoke! However to be fair, some volume quality car manufacturers supply their comparable replacement parts at quite high cost?!
9. With the major components re-engineered I felt it essential to have some of the important accessories improved, particularly the oil pump, filtration and supply system; this meant a redesign of the sump to accommodate a larger oil pump (in production), spin on filter and the pressure relief valve (in the correct position after the filter). All this work is completed with parts on the shelf or nearly. The PVT water pump was a problem so that has been re-designed & appears to work well, better starter motors were thought essential using pre engaged high torque motors - now available.
10. After a frustratingly long delay I have now received the new design cylinder head casting in Aluminium which has the potential for improved porting and will fit Vintage, PVT & post war engines. This together with the new Camshaft and rocker design will with some confidence offer significant performance improvements whilst still conforming to the original design concept. I find we are now entering the "exciting period" of nearing a complete engine build which I hope will be done this year, this will incorporate all the above and along with better rocker shafts, flywheels, liners and pistons.A new head gasket is in progress which I hope will offer better sealing performance so there is still some work to do, not least a better Rocker/Camshaft cover to top it all off.
11. The next part of the program will be engine performance trials, development of the carburetion and ignition systems; these will require the support of experts in this field, but this can be done progressively, and by other users who require different results - whether it be general road performance, sprinting, track work or hill climbs.The Weller engine is well thought of by both AC Owners & Frazer Nash Owners, the overriding objective has developed to achieve at least as good performance as the BMW 328/Bristol engines and if this is attained perhaps the original AC ACE Owners will suddenly find respect from the Bristol engined car owners and match their competitive performance! - with a simpler (superior) engine.
All the information on the project is available on my web site ' www.ac-engine.com ' it will be updated periodically but attached are some pictures of the various parts which essentially can be fitted to existing engines with some restrictions, I am more than happy to discuss the project with interested people & have I hope given assistance to people already. I have invested a great deal of time & capital, it would be nice if this can be available to others, I will have my own engines assembled soon & fitted to my cars. I hope you find this project of interest.
Robin A Woolmer
AC Engine Project
AC Action Article July 2008
